/Engine/Source/Developer/BSPUtils/Public/BSPOps.h
Validate a brush, and set iLinks on all EdPolys to index of the first identical EdPoly in the list, or its index if it's the first. Not transactional.
static void bspValidateBrush ( [UModel](API\Runtime\Engine\UModel) * Brush, bool ForceValidate, bool DoStatusUpdate )